RBS and NatWest say that the range is exclusive to its current customers because they want to "reward loyalty by offering the best rates possible".

The fixed rate mortgage is available for two, three, five, seven or ten years, and there are two sets of rates – 6.19 per cent for people who only need a loan to value (LTV) of 75 per cent, and 6.54 per cent for customers who need an LTV of up to 95 per cent.

The tracker rate on a 75 per cent LTV is available at 5.99 per cent and for a 90 per cent LTV, the rate is 6.14 per cent. All of the new deals have a fee of £899.

"In these uncertain times we are committed to helping our existing customers who are about to come to the end of their current deal," said Jon Cooper, head of mortgages for existing customers.

"We have introduced these new competitive rates to support customers who want to keep monthly repayments as affordable as possible."